Apparatus for developing exposed photographic prints



A. L. MAYER Jul 15, 1946.

APPARATUS FOR DEVELOPING EXPOSED PHOTOGRAPHIC PRINTS Filed Oct. 6, 1941R E S A 5 R OM T... y NL D OOOOOOOOOOO OO r v A Patented July 16, 1946UNITED STATES PATENT OFFICE APPARATUS FOR DEVELOPING EXPOSEDPHOTOGRAPHIC PRINTS 8 Claims. 1

This invention relates to photographic equipment, and more particularlyto apparatus for continuously developing exposed photographic prints.

An object of the present invention is to provide apparatus into whichindividually exposed, but undeveloped prints may be fed, and from whichthey will be discharged completely developed, fixed and washed ready fordrying.

Another object of the invention is to provide a device having thehereinabove described characteristics, wherein all the various stepsfollowed incident to developing an exposed print may be under thesupervision of an attendant, who may, whe occasion demands, accelerateor retard the rate of travel of certain individual prints in accordancewith their particular rates and degrees of reaction to the developingprocess, whereby the prints being automatically developed may,nevertheless, be under the direct personal supervision of an attendant.

Still another object of the invention is to provide in a device of thecharacter stated, means for directing streams of developer, rinse Water,hypo solution and rinse water onto the prints as they are conveyedthrough the device in such a manner that the individual prints aremoistened rather than soaked, as is the case when prints are run throughor immersed in a bath.

Another object of the invention is to provide a developer wherein onlythe sensitized side or face of the sheets of exposed printing paper issubjected to the action of the developer solution, the first wash andthe subsequent action of the fixing or hypo solution, with the resultthat the prints after their final washing may be rapidly dried, therebyconsiderably shortening the overall time required to produce thefinished print, without sacrificing quality of the finished product.

Another object of the present invention is to provide an improved printconveyer for an automatic. continuous print developing device, saidconveyer being designed whereby to effectively preclude shifting orslipping of the prints upon and relative to the conveyor.

Still a further object of the invention is to provide a fully automaticmulti-tank, developing device for individual prints, wherein thechemical solutions of the various tanks are recirculated throughindividual circuits.

These and other objects are attained the means described herein anddisclosed in the accompanying drawing, in which:

Fig. 1 is a side diagrammatic view of one em- 2 bodiment of the devicecomprising the present invention.

Fig. 2 is a top plan view of the device of Fig. 1.

Fig. 3 is a fragmental top plan View of a conveyer belt which comprisesa detail of the present invention.

Figs. 4 and 5 are modifications of drive means for precluding slippingof individual prints relative to their conveyer belt as they aresubjected to the action of the developer, wash and hypo solutions.

Fig. 6 is a modified type of fluid discharge means, which comprises adetail of the present invention.

Fig. '7 is a single belt conveyer system which may be used in place ofthe three belt system disclosed at station M of Fig. 1.

With particular reference to Fig. 1, it will be observed that thepresent device may comprise a conveyer system upon which exposed, butundeveloped photographic prints may be placed whereby to be subjected tothe successive action of a developer solution, a water rinse, a fixingbath, and another water rinse. The prints upon discharge from the deviceare adapted to be transferred directly to a print drying machine, of anysuitable design.

In the particular embodiment of the invention illustrated, the conveyersystem comprises a plurality of short, independent conveyors denotedgenerally by the numerals iii, ll, l2, l3, M and I5, driven byappropriate means, not illustrated.

For brevity of description and clarity of detail, it will be assumedthat the present device comprises four stations, denoted generally bythe letters J, K, L and M.. Station J may comprise a developer stationat which exposed prints may be subjected to the action of any suitabledeveloper solution; station K may comprise a rinse station at which anydeveloper solution carried over from station J is washed from theprints; station L may comprise a fixation station at which the washedprints from station K are subjected to the action of a fixing solution;station M may comprise a second rinse station at which the fixersolution from station L is washed from the prints. In the preferredembodiment of the invention, separate conveyer means such as Ill, H andi2 may be provided for imparting a linear motion to the prints formoving them through stations J, K and L respectively, and other separateconveyer means such as I3, l4 and I5 may be provided for moving theprints through station M, for reasons hereinafter made more fullyapparent.

With particular reference now to stations J and L, it will be observedthat the developer solution D and the fixer solution F are adapted to becontinuously circulated from their respective tanks 20 and 2! throughconduits 22 thence to discharge nozzles 23, by means of suitablerecirculating pumps P thereby permitting the solutions to be used overand over. It should be observed that the lower reaches H9 and N2 ofconveyers Ill and i2 respectively are disposed above the level of thefluids normally housed in tanks 26 and 2! by an amount sufficient topreclude wetting of said lower reaches incident to the normal operationof the device, By reason of such an arrangement the receiving ends it ofthese conveyers, will be substantially free of the fluids housed Withintanks 2;) and fl, except for such fluid discharged from 23 as may beretained on the conveyers.

With reference now to stations K and M, it will be observed that asupply of rinse water from suitable supply pipes 25 is adapted to bedischarged onto the upper reaches of conveyer means II, It, Hi and i5,thence into drain pans 26 from which it may be discharged into suitablesewer connections denoted generally by the numerals 21 and 28.

Individual sheets of exposed, but undeveloped prints are adapted to beplaced on the charge end 16 of conveyer m which will impart a linearmotion thereto through station J and transfer the prints onto conveyer lI from which they will be transferred onto the conveyer l2, and thenceonto conveyer [3. At this point it should be observed that the printsremain with their front, sensitized face uppermost as they are movedthrough stations J, K, L and onto conveyer E3 of station lVl. However,as the prints are transferred from conveyer I3 to conveyer 54 they areturned over thereby disposing their backs or rear, unsensitized surfacesuppermost, and as the prints are transferred from conveyer M to conveyerthey are once again turned over for disposing their top surfacesuppermost. It has been found that by subjecting only the top, sensitizedsurfaces of the prints to the successive actions of a developersolution, a rinse solution, a fixer solution and a second rinsesolution, that the prints are moistened as contrasted to the soaking towhich they would be subjected if they were wholly immersed in thevarious solutions. The practical result of moistening the prints ratherthan soaking them, is two-fold, viz., inasmuch as the underside of theprints are subjected to very little, if any, of the developer and fixedsolutions, the prints may be thoroughly washed much faster than hasheretofore been possible; and the prints after being thoroughly washedmay be dried much faster since the print has not had an opportunity tosoak up much moisture.

The reversal or overturning of the prints as above described, resultsfrom the fact that by the time the prints reach the discharge end ofconveyer I3, they have become sufficiently wet to lose most of theirstiffness, and will accordingly tend to adhere to the conveyer belt andfollow the belt toward the return reach thereof. However, the waterspray from 25 will strike the trailing ends of the prints as the printsproceed to the lower reach of the belt, thereby dislodging them anddepositing the prints in overturned condition upon the underlying upperreach of conveyer belt Hi. It is for this reason that belts l3, l4 andit are made to overlap at their ends, with a substantial verticaldistance between them. This behavior of the prints does not occur atstations J, K and L, for the reason that in the earlier stages of theprocess the prints retain enough of their initial rigidity to cause themto bridge the gaps between conveyers l0, ll, 12 and it, which aresubstantially coplanar. Moreover, each successive conveyer belt is inposition to pick up a print at its leading edge, and to perpetuateadvancement thereof face up. At conveyer belts l3, l4 and I5, however,the prints are free to follow the belts around the ends of theconveyers, until the prints are reversed or overturned and thendislodged by the water spray.

In order to provide means for holding the individual prints on the upperreach of the various conveyers without shifting, and in order that thevarious solutions discharged onto the upper reaches may be drained off,the ccnveyers are preferably constructed with a plurality of holes, orperforations, such as disclosed in 3. It has been found that prints,denoted generally by the numeral ii], when placed on a belt per--forated as disclosed in Fig. 3 will not be shifted or floated around bythe action of the various solutions discharged thereon, as is the casewhen a substantially solid belt is used. It is believed that theperforations 2M permit a suction to be created between the underside ofthe prints and those perforations covered by the prints, such asperforations MI, and this condition is emphasized by reason of the factthat any fluid which would otherwise stand on the belt is drainedthrough the uncovered perforations 24! which surround the variousprints. If desired, the conveyer belt may be fabricated from canvas,rubber, or the like, suitably perforated, or it may comprise a metallink belt, wherein the spacing around the individual links functionsprecisely as the perforations 24! of the belt disclosed in Fig. 3.

With particular reference now to station J of Fig, i, it will beobserved that the developer so lution spray nozzles 23 are adapted tomoisten the prints carried by conveyer IQ for but por tion of the linealdistance between receiving end It and discharge end 36, whereby thechemical action of the developer solution in reducing the lightsensitive gold or silver salts of the upper, sensitized surfaces of theprints to a metallic state is permitted to continue in the atmosphere,and without the addition of more developer solution. Experiment hasindicated that the results obtained by subjecting an exposed film todeveloper solution for forty seconds and in permitting the chemicalreaction to continue in the atmosphere for ten seconds, are far superiorto the results obtained when the same type of prints are subjected tothe direct action of developer solution for fifty seconds. It should beunderstood that the values mentioned in the foregoing example areexemplary rather than restrictive, and are not intended to indicatecritical limits, since the ratio of length of time during which anexposed print is subjected to the direct action of a solution to thelength of time in which the developing action of the fluid is permittedto occur in the atmosphere may vary for different films, the particularconcentration of developer solution, and other well-known, variablefactors. Inasmuch as the present device is primarily adapted forindividually developing and fixing exposed photographic prints on acommercial scale, it will be appreciated that there will be a certainamount of variation in the physical and chemical characteristics of theexposed prints fed into the device which will result in difierent ratesof development of the prints, in other words some of the prints will bedeveloped at a faster rate, and other prints will be developed at aslower rate than the average rate required for most of the prints runthrough the device. In order that the rate of development of the variousprints passing through station J may be controlled, it is desirable thatan attendant be stationed at this station whose duty it is to observe.the rate of development of the various prints disposed on the upperreach of conveyer It). In the event that the rate of development of anyparticular print is excessive, the attendant willpreferably manuallyretrieve said print'and place same on a high speed belt I50 which willrapidly transfer the print to a fixing :bath B0, or he may plunge saidprint directly into. a fixing bath oonveniently located adjacent stationJ. In this manner many of those prints which would hitherto beover-developed and thereby rendered useless, may be saved. In'the eventthat the attendant should observe. that the rate of development ofcertain prints is too slow, he may retrieve these prints and place'themon conveyer III for another passage under nozzles 23.

The prints upon reaching discharge end 36 of conveyer ID are adapted tobe transferred to the upper reach of conveyer H which is adaptedto move.them beneath the streams 31 of rinse water. The prints are thentransferred onto the receiving end I 6 of conveyer l2 which moves themunder nozzles 23, from which quantities of fixing solution aredischarged.

With particular-reference now to station M, it will be observed that theprints will be thoroughly Washed on both sides-by reason of therelationship of conveyers l3, and I5. Experiment. has indicated thatwhen prints are turned but twice while being subjected to the action ofrinse water that all traces of the fixer solution are effectivelyremoved from the prints. which may then be fed, by means of a suitableconveyor. not illustrated, to a print drying device, not illustrated.

As indicated in Fig. 1, stations J K and L; are preferably located in adark room, whereas station M may, if desired, be located outside of thedarkroom.

In those instances where it is desired to eliminate nozzles, theconstruction disclosed in Fig. 6 may be utilized for dispensing thevarious solutions onto the upper reaches of the various conveyers. Byreason of the construction disclosed in Fig. 6, the various. nozzles23-may-be dispensed. with and the same effect gained by providing aplurality of spaced apertures 50 in the bottom. element 5| of a tank ortrough denotedgenerally by the numeral 52. The fluid from tanks 28 and21 may now be piped by means of conduit 22 into trough or container 52from which it may flow by gravity through holes 50. If desired, thissystem may be likewise used at stations K and M for distributing rinsewater onto the conveyors and prints disposed thereon.

If desired the three conveyer units I3, NY and I5 may be replaced by theone unit disclosed in Fig. '7 wherein one long belt; is caused to passaround an arrangement of pulleys, whereby the same result is obtained asgained by means; of the three conveyors of station M. In those instanceswhere it is desired to immerse individual prints in developer, rinse,fixer and final rinse solutions, the constructions disclosed in Figs. 4and 5 may be applied, wherein means for preventing relative motion ofthe individual prints relative to the upper reach of a conveyer whilethe prints are immersed in the solutions are disclosed. In Fig. 4 aplurality of idler pulleys denoted generally by the numeral 69 aresuitably mounted above the upper reach III of conveyer H] whereby tohold the prints against the conveyer belt. It should be understood thatpulleys 60 may be mounted for rotation about their longitudinal axes 6|,by appropriate means, not disclosed.

In Fig. 5 the individual prints are adapted to be held in place upon theupper reach III of conveyer ID by means of the lower reach H3 of anendless belt H4 which extends around a pair of spaced pulleys H5 and H6,as shown. It should be understood that although only conveyer ID isillustrated in Figs. 4 and 5, the print holding means disclosed in thesefigures could be applied to all of the conveyers upon which the printswould be transferred as they pass through the device.

For clarity of understanding, it should be understood that the termdevelopment as used herein relates to the process of rendering visiblethe image on an exposed photographic film usually by reduction of goldor silver salts to the metallic state, and that the term developersolution relates broadly to any reducing liquid used in photography forrendering the image on an exposed print visible by the formation ofblack metallic silver. The process of fixation relates to the process ofdissolving the light sensitive gold or silver salts from the films orprints, thus making them insensitive to the further action of light, andthe term fixing bath or fixer solution as used herein relates to anysolution used for the fixation of photographic plates, films, or papers.

It should be understood that various modifications and changes may bemade in the structural details of the device, such as, by way ofexample. providing the various stations J K, L and M in vertical, ratherthan horizontal alignment and of enclosing the device in a cabinet typehousing. within the scope of the appended claims, without departing fromthe spirit of the invention.

It should be noted. that if desired in some instances, additional spraynozzles 23 may be pro vided at station J in order that the printscarried by conveyor I I! will be subjected to the direct action of thedeveloper solution for the entire lineal distance between points it and35. Such a procedure would be followedin those instances where thepresent device is used to continuously iiivelope exposed photographicfilms, and the With reference. to Fig. 2 it will be understood thatsuitable means, not illustrated, may be provided for transferring theprints from fixer bath to rinse station M.

What is claimed is:

1. A device of the class described for developing exposed photographicprints, said device comprising an open topped receptacle, a perforatedconveyor for moving said prints individually in a fiatwise manner faceup, above said receptacle. and applicator means for spraying a developersolution onto the upper face of said prints and the perforated conveyorsupporting the prints, said conveyor in the area beneath the sprayapplicator having its perforations unrestrictedly open to affordimmediate drainage of the solution through the conveyor Where thesolution strikes the conveyor, the length of conveyor travel exceedingthe area covered by said spray means whereby the prints willbe exposedto the action of the developer solution for a limited length of timeless than the total time required for complete development of theprints, and then be exposed to the atmosphere with the conveyor and theprints thoroughly drained of developer solution, until the developmentaction is complete, and means for recirculating the drained developersolution from the receptacle to the spraying means.

2. In a device for treating exposed individual photographic printshaving sensitized front surfaces and non-sensitized rear surfaces, thecombination of bath means including a traveling endless conveyer belthaving through drainage perforations, for advancing a series of printswith their sensitized surfaces exposed upwardly, while the rear surfacesthereof rest flatwise in such full contact upon the conveyer belt as toprotect said rear surfaces from substantial exposure to liquid sprayeddownwardly toward the belt and onto the sensitized surfaces of theprints, the perforations of the belt being unrestrictedly open, and sospaced and numbered as to be disposed beneath and about each print, witha sui'licient number of perforations remaining exposed for immediatelydraining the sprayed liquid from the belt and precluding floatation ofthe prints, and an overhead applicator for spraying treating liquiddownwardly onto the belt in the area of the unrestrictedly openperforations thereof, in such quantity as would float the prints in theabsence of the immediate drainage aforesaid.

3. In a device for treating exposed individual photographic printshaving sensitized front surfaces and non-sensitized rear surfaces, thecombination of bath means including a single thickness endless conveyerbelt means having through drainage perforations, for advancing a seriesof prints with their sensitized surfaces exposed upwardly, while therear surfaces thereof rest flatwise in such full contact upon theconveyer belt as to protect said rear surfaces from sub stantialexposure to liquid sprayed downwardly toward the belt and onto thesensitized surfaces of the prints, the perforations of the belt beingunrestrictedly open, and so spaced and numbered as to be disposedbeneath and about each print, with a suflicient number of perforationsremaining exposed for immediately draining the sprayed liquid from thebelt and precluding flotation of the prints, and means for sprayingtreating liquid as stated, in such quantity as would float the prints inthe absence of the perforations aforesaid, said conveyer belt means andspraying means being arranged in multiples, with successive conveyerbelt means aligned to pass the individual prints from one of said beltmeans to the next, sensitized surfaces uppermost, and rinsing means forthe prints comprising an overhead water spray, and a series of drivenendless belts having upper reaches traveling in a common direction, andin stepped spaced relationship one to another with the reaches ofsuccessive rinse belts each underlying the reach of a preceding rinsebelt, whereby any print in leaving one rinse belt is uninfluenced by asucceeding rinse belt, and therefore tends to follow said one rinse belttoward its lower reach, thereby exposing the trailing edge of such printto the overhead water spray to initiate dislodging the print anddepositing it upon the underlying portion of the next succeeding rinsebelt in an overturned con dition.

4. In a device for treating exposed individual photographic printshaving front and rear faces,

the combination which comprises means for advancing the individualprints in flatwise condition and in succession, a liquid spraying deviceto rinse the prints, and a series of driven endless belts having upperreaches traveling in a common direction, said reaches being in steppedspaced relationship to one another, with the reaches of successive beltseach underlying the reach of a preceding belt, whereby any print inleaving one belt is uninfluenced by a succeeding rinse belt, andtherefore tends to follow said one belt toward its lower reach, therebyexposing the trailing edge of such print to the liquid discharged fromthe overhead spraying device to initiate dislodgment of the print anddeposit thereof in an overturned condition upon the underlying portionof the next succeeding belt.

5. Automatic equipment for processing individual exposed photographicprints, comprising in combination an aligned succession of separatedeveloping, rinsing, and fixing means, including belt conveyors arrangedto advance individual prints substantially continuously with theirimage-carrying faces exposed, means for spraying developing, rinsing,and fixing liquids onto said print faces as the prints are advanced bythe succession of conveyor belts in the order stated, and print washingmeans arranged to receive the prints from the conveyor of the fixingmeans, including a succession of moving conveyor belt reaches travelingin a common direction, said reaches having curved end portions overlyingone another in spaced relationship and to which the wet prints adherewhile following the curved end portions, thereby reversing the prints atthe end of each of said conveyor reaches, and sprays of washing fluid sodirected at the prints as they follow said curved end portions' of theconveyor reaches, as to dislodge the prints therefrom and effect depositthereof onto the next succeeding conveyor reach in an overturnedcondition.

6. In a device for treating exposed individual photographic printshaving sensitized front surfaces and non-sensitized backs, thecombination of bath means including an overhead treating fluidapplicator, and a perforated traveling belt beneath the applicatorarranged for advancing a series of prints past the applicator with theirsensitized surfaces exposed upwardly, while the backs thereof cover someonly of the perforations and rest flatwise in contact with the belt, theperforations of the belt not covered by the prints being unrestrictedlyopen beneath the applicator, to afford immediate drainage of treatingfluid where the fluid strikes the belt and the prints superposedthereon.

'7. In a device for treating exposed individual photographic printshaving sensitized front surfaces and non-sensitized backs, thecombination of bath means including an overhead treating fluidapplicator, and a perforated traveling belt beneath the applicatorarranged for advancing a series of prints past the applicator with theirsensitized surfaces exposed upwardly, while the backs thereof restflatwise in contact with the belt to protect the backs of the printsfrom substantial exposure to treating fluid from the ap plicator, theperforations not covered by the prints being unrestrictedly open beneaththe applicator to afford immediate drainage of treating fluid where itstrikes the belt and the prints superposed thereon, said perforationsbeing so spaced and numbered as to be disposed beneath and about theprints with a sufiicient number of 9 perforations openly exposed in theregion of application of the treating fluid, to freely drain the fluidand prevent flotation of the prints.

8. In a device for treating exposed individual photographic printshaving sensitized front surfaces and non-sensitized backs, thecombination of bath means including an overhead treating fluidapplicator, and a perforated traveling belt beneath the applicatorarranged for advancing a series of prints past the applicator with theirsensitized surfaces exposed upwardly, while the backs thereof restflatwise in contact with the 10 belt to protect the backs of the printsfrom substantial exposure to treating fluid from the applicator, theperforations not covered by the vprints being unrestrictedy open beneaththe applicator to afford immediate drainage of treating fluid Where itstrikes the belt and the prints superposed thereon, the travel of thebelt being extended sufliciently beyond the area of treating fluidapplication to complete the exposure of the prints in the presence ofatmospheric air freely accessible thereto.

ALVIN L. MAYER.

